Improvement in valve-gear for steam-engines



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Letters Patent No. 108,137, dated October 11, 1870.

H IMPROVEMENT IN VALVE-GEAR FCR STEAM-ENGINES.

The Schedule referred to in these Letters Patent and making part of thesame'.

To all whom it 'may concern:

Be 'it known that I, THOMAS HILL, of Vallejo, county of Solano, State ofCalifornia, have invented an Improved Valve-Gear for Steam-Engines; andI do hereby declare the following description and a'ccompanying drawingare sufficient to enable any person -skiled in the art or science towhich it most nearly appertains to make and use my said invention orimprovements without further invention or experiment.

The object of my invention is to provide certain improvements in thevalve-gear ot' steamlengines, by the use of which I 'am enabled todispense with a portion ot'- the mechanism hitherto found indispensable.

My invention has been more especially developed to apply to doubleoscillating marine-engines, and,

by its use only one link and two eccentrics are nec-v essary, in orderto reverse both engines, and run them in either direction, and by aslight modification only one eccentric will be needed.

Besides marinefcngines, my invention ca'n be applied to other forms, andespecially locomotives.

Referring to the accompanying-drawing for a more.

complete explanation of myinvention'- A Aare two'cylinders of anoscillating engine, to which, in the present case, I have applied myinvention'.

v B B are the steam-chests and valve-chambers.

The cylinders are mounted so as to oscillate upon trunnions at C,receiving steam through the branchpipes D D and exhausting at E.

A rock-shaft, F, extends across, between, and' above the cylinders,being supported upon the frame G. v

At one end of this shaft is fastened a rocker-arm, H, a pin in itsouter'end entering the slot' vin the link I, and upon this the linktravels ywhen the engine is reversed. A

This is effected by the reverse-lever J and counesting-rod K, which isVpinned to thc end of 'the link.

Two eccentric-rods L L are pinned to the lugs a a, on the inside of .thelink, and through these the eccentrics M actuate the link.

At the opposite end -of the shaftF lfrom'the link arises anotherrocker-arm, N, 4so formed as to have two points of attachment for theconnectingrods o o', by which the valves of the two engines areactuated. s

At the lower end of each of these rods is secured a link, P, at rightangles to the rod, and having a The 'exhaust-port .f is made as shown,itssides forming a curve from each other, thus allowing the steamtoescape freely.

In order to communicate motionfrom the valvespindle, a short arm, t', iskeyed to it, and projects downward into :in-,opening in the top ofthevalve, so as to have a sort of rolling'motion, resembling that oftheball-and-socket joint'.

The operation of my engine is as .follows The link being moved or set bythe reverse lever,

so as to bring the pin of the rocker-arm H under the influence of eitherof the cccentrics M, the shaft F will-'be turned alittle way, so"thatthe valves will, through their connections, receive a dilerentset fromthat given by the other eccentric, and the motion of thefenginc will bereversed.

f One eccentric might be employed, by constructing the upper end of theeccentric-rod as shown in Figure 4, a slot being made at m, so that asthe pin a is thrown from one side tothe other of the link it can travelup and down this slot.

This is rendered necessary from the'fact that the link I is, in thiscase, keyed to the shaft Ifat the point 'r,; and thus communicatesmotion to it.

` The end ot' the link, by a'. cam, s, operated by the lever J'.

It is also possible to operate thevalves by the oscillationsof theengine` alone.

For this purpose the' valve-stem c has, in addition to the crank-arm It,a short arm, u, which connects it with the vibratory arm VL This arm isconnected, by arod, w, to the arm` 'X, which is pinned to the frame,"asshown at Fignre 5.

The arm X is stationary, except when reversing the engine, when itsmovements change the set of the valves.

By means of the arms R u vw the Yvalves are operated by the simpleoscillations of the engine.

Having thus described my invention,

What I- claim, and desire to secure by Letters -Patentisl. The devicefor operating both valves lfrom one rock-shaft, consisting of the doublearm` N, the rods O 0', with their transverse links P and the arms R onthe valve stem, substantially as herein described.

2. Theli-nk I, and either one or more eccentrics and rod or rods L, inconjunction with mechanism, asy described, for operating thevalve-gear'of connected engines, substantially as set forth'. v

In witness' that the above-described invention is claimed by me, I havehereunto set my hand and seal.

THOMAS HILL. [L s.}

Witnesses z Gao. H. Stroxe, WM.. It. Booms.

pin n is secured, after it arrives at either

